<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <script>
    let day=prompt('请输入星期数')
    switch(day) {
      case'星期一':alert('Monday')
      break
      case'星期二':alert('Tuesday')
      break
      case'星期三':alert('Wednesday')
      break
      case'星期四':alert('Thursday')
      break
      case'星期五':alert('Friday')
      break
      case'星期六':alert('Saturday')
      break
      case'星期日':alert('Sunday')
      break
      default:
      alert('一周只有七天')






    }
  </script>
  
</body>
</html>